For the purpose of this chapter the following definitions shall apply unless the context clearly indicates or requires a different meaning.
"Approved"means accepted by the general manager as meeting an applicable specification stated or cited in this title, or as suitable for the proposed use.
"Auxiliary water supply"means any water supply on or available to the premises other than the purveyor's approved public water supply will be considered as an auxiliary water supply. These auxiliary waters may include water from another purveyor's public potable water supply or any natural source(s) such as a well, spring, river, stream, harbor, and the like or used waters or industrial fluids. These waters may be contaminated or polluted or they may be objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
"Backflow"means the flow of any foreign liquids, gases or substances into the distributing pipe lines of a potable supply of water. Backflow may occur under two conditions: pressure greater than atmosphere (see "backpressure" below); and pressure that is subatmospheric (see "back siphonage" below).
"Backflow preventer"means an assembly or means designed to prevent backflow.
1. "Air gap"means unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing, fixture or other device and the flood level rim of the vessel. An approved air-gap shall be at least double the diameter of the supply pipe, measured vertically, above the overflow rim of the vessel; and in no case less than one inch.
2. "Double check valve assembly"means an assembly of two independently operating approved check valves with tightly closing shut-off valves on each end of the check valves, plug properly located test cocks for the testing of each check valve. The entire assembly shall meet the design and performance specifications as determined by a laboratory and field evaluation, program resulting in an approval by the health officer and approved by the AWWA for backflow prevention assemblies. To be approved these assemblies must be readily accessible for in-line testing and maintenance.
3. "Reduced-pressure-principle backflow prevention device"means an assembly containing a minimum of two independently acting approved check valves, together with an automatically operated, pressure differential relief valve located between the two check valves. During normal flow and at the cessation of normal flow the pressure between these two check valves shall be less than the upstream (supply) pressure. In case of leakage of either check valve, the differential relief valve, by discharging to the atmosphere, shall operate to maintain the pressure between the checks at less than the supply pressure. The unit must include tightly closing shut off valves located at each end of the device, and each device shall be fitted with properly located test cock. When the inlet pressure is two pounds per square inch or less, the relief valve shall open to the atmosphere. To be approved these assemblies must be readily accessible for in-line testing and maintenance and be installed in location where no part of the assembly will be submerged.
"Backpressure"means backflow caused by a pump, elevated tank, boiler or other means that could create pressure within the system greater than the supply pressure.
"Back siphonage"means the flow of water or other liquids, mixtures or substances into the distribution pipes of a potable water supply from any source other than its intended source caused by the reduction of pressure in the potable water supply system.
"City"means the city of Lathrop.
"Contamination"means an impairment of the quality of the potable water by sewage, industrial fluids or waste liquids, compounds or other materials to a degree which creates an actual or potential hazard to the public health through poisoning or through the spread of disease.
"Cross-connection"means any physical connection or arrangement of piping or fixtures between two otherwise separate piping systems, one of which contains potable water and the other non-potable water or industrial fluids of questionable safety, through which, or because of which, backflow may occur into the potable water system. This would include any temporary connections, such as swing connections, removable sections, four-way plug valves, spools, dummy section of pipe, swivel or change-over devices or sliding multi-port tube.
"Cross-connections (controlled)"means a connection between a potable water system and a nonpotable water system with an approved backflow prevention assembly properly installed and maintained so that it will continuously afford the protection commensurate with the degree of hazard.
"Cross-connection control by containment"means the installation of an approved backflow prevention assembly at the water service connection to find and permanently eliminate or control all actual or potential cross-connections within the customer's water system; or, it shall mean the Installation of an approved backflow prevention assembly on the service line leading to and supply a portion of a customer's water system where there are actual or potential cross-connections which cannot be effectively eliminated or controlled at the point of the cross-connection.
"General manager"means the city engineer, or the city official, or his or her duly authorized agent, responsible for the implementation of this chapter, including, but not limited to, the duly appointed manager of the city water system, who is invested with the authority and responsibility for the implementation of an effective cross-connection control program and for the enforcement of the provisions of this chapter.
Hazard, Degree of."Degree of hazard" means the term is derived from an evaluation of the potential risk to public health and the adverse effect of the hazard upon the potable water system.
Hazard, Health."Health hazard" means any condition, device or practice in the water supply system and its operation which could create, or in the judgment of the State Department of Health Services, local health agency or the general manager may create a danger to the health and well-being of the water consumer.
Hazard, Plumbing."Plumbing hazard" means a plumbing-type cross-connection in a consumer's potable water system that has not been properly protected by an approved air-gap or approved backflow prevention assembly.
Hazard, Pollutional."Pollutional hazard" means an actual or potential threat to the physical properties of the water system or to the potability of the public or the consumer's potable water system, but which would constitute a nuisance or be aesthetically objectionable or could cause damage to the system or its appurtenances, but would not be dangerous to health.
Hazard, System."System hazard" means an actual or potential threat of severe damage to the physical properties of the public potable water system or the consumer's potable water system or of a pollution or contamination which would have a protracted affect on the quality of the potable water in the system.
"Health officer"means State Department of Health Services Officer or a representative or the local health agency representative.
"Industrial fluids systems"means any system containing a fluid or solution which may be chemically, biologically or otherwise contaminated or polluted in a form or concentration such as would constitute a health, system, pollutional or plumbing hazard if introduced into an approved water supply. This may include, but not be limited to: polluted or contaminated waters; all types of process waters and used waters originating from the public potable water system which may have deteriorated in sanitary quality; chemicals in fluid form; plating acids and alkalines, circulating cooling waters connected to an open cooling tower and/or cooling towers that are chemically or biologically treated or stabilized with toxic substances; contaminated natural waters such as from well, springs, streams, rivers, bays, harbors, seas, irrigation canals or systems, and the like; oils, gases, glycerine, paraffins, caustic and acid solutions and other liquid and gaseous fluids used in industrial or other purposes or for firefighting purposes.
"Pollution"means the presence in water of any foreign substance (organic, inorganic, radiological or biological) which tends to degrade its quality so as to constitute a hazard or impair the potability or usefulness.
"Public water system"means any potable water supply approved by or under the public health supervision of a public health agency of the state or local health agency.
"Service connection"means the point at which the public piping begins. If a meter is installed as part of public water system then the term "service connection" shall mean the stream end of the meter.
Water, Nonpotable."Nonpotable water" means water which is not safe for human consumption or which is of questionable potability.
Water, Potable."Potable water" means any water which, according to recognized standards, is safe for human consumption.
"Water service connection"means the terminal end of a service connection from the public potable water system; that is, where the water purveyor loses jurisdiction and sanitary control over the water at its point of delivery to the customer's water system. If a meter is installed at the end of the service connection, then the service connection shall mean the downstream end of the meter. There should be no unprotected takeoffs from the service line ahead of any meter or any backflow prevention assembly located at the point of delivery to the customer's water system. "Service connection" shall also include water service connections from a fire hydrant and all other temporary or emergency water service connections from the public potable water system.
Water, Used."Used water" means any water supplied by a water purveyor from a public potable water system to a consumer's water system after it has passed through the point of delivery and is no longer under the sanitary control of the water purveyor.
"Water purveyor"means any person, corporation, public utility, municipality, district or other agency or institution that operates a public water system.
(Prior code § 53.62; Ord. 25-476, 12/8/2025)